Apparatus for transferring fluids



Nov. 28, 1950 .1. B. HUNTER ETAL APPARATUS FOR TRANIFERRINQ FLUIDS Filed Jan. 28, 1946 E N T T A JAMES B HUNTER ROBE/P7' C. TAYLOR W/LL/AM S. YOUNG y Patented Nov. 28, 1950 APPARATUS FOR TRANSFERRXNG FLUEDS .lames B. Hunter, Upper Darby, Robert C. Taylor,

Melrose Park, and William S. Young, Philadelphia, Pa., assignors to Consolidated Engineering Corporation, Pasadena, Calif., a corporation of California Application January 28, 1946, Serial No. 643,942

19 Claims.

This invention is concerned with the transfer of light uids, both liquid and gaseous, from one container to another and provides novel lmeans for effecting such transfer while maintaining a seal at the transfer point to prevent the inux of atmospheric contaminants, etc.

vIn analytical apparatus such as mass spectrom-f eters and infra-red spectrometers, nuids to be analyzed should be introduced into the sampling system of the apparatus without introducing a contaminant, such as air. Heretofore this has been accomplished through valves, stop cocks, and the like, but such devices are not entirely satisfactory. The moving parts of Valves, etc. present an opportunity for leakage, and lubricants employed to seal the moving parts may contaminate the sample or absorb part of it.

A co-pending application Serial No. 642,376, led January 19, 1946, now Patent No. 2,452,623, issued November 2, 1948, describes and claims a system for sample introduction involving no moving parts. However, this system is suitable only for the introduction of liquids and does not serve when gaseous samples are to be introduced. In accordance with the present invention, any light Huid, be it gaseous or liquid, may be transferred from one container to another while maintaining a seal between the two. This is accomplished by providing a seal composed of a porous member that is pervious to the light fluid to be introduced but impervious to a heavy liquid (say, mercury) in which the light fluid is substantially insoluble and immiscible. Theporous member is attached to a conduit or container into which the light fluid is to pass and is covered at its opposite face with a pool of heavy liquid. The light liquid to be transferred is placed in another container provided with a second porous member having characteristics similar to that of the first, i. e. it is pervious to the light liquid but impervious to the heavy liquid. The second porous member is so constructed that it may be brought into contact with the first member within the pool so as to displace the heavy liquid between the two members and permit the flow of the fluid between the two members, means for reducing the pressure between the two members being provided to induce such flow.

The second porous member may be retained in the pool covering the rstporous member but out of contact with the latter. Or the second porous member, may be placed in an auxiliary well and covered therein with a second pool of f the heavy liquid. If this well is attached to the second member and. 1S Smell?? llfl'lllat in which the rst porous member is disposed, it may be inserted into the larger well and contact thus made between the two members.

Mercury is, in most instances, a suitable heavy y,liquid since aqueous solutions and many organic liquids are substantially insoluble in it.

The porous members may be made of any suitable material. Disks made by sintering together small siliceous particles are desirable, care being taken to control the size of the pores.

These and other aspects of the invention will be apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a sectional elevation through a preferred form of my invention in which the entire sample container may be immersed in a well of the heavy fluid;

Fig. 2 is a sectional elevation of a modification of the apparatus of Fig. 1 in which the porous member attached to the sample container communicates therewith through a connection which permits the sample container per se to remain outside the well;

Fig. 3 is a sectional elevation of another type of the apparatus of my invention in which theA Referring to Fig. 1, it will be seen that the apparatus comprises a well lll in the general form of a test tube with an enlarged upper section l l. A pool I2 of heavy liquid, such as mercury, is contained in the well with its upper surface adjacent the top thereof.

A sample conduit I3 projects downwardly into the upper portion of the well and its lower end is closed by means of a porous disk I5 made by sintering together particles of glass. The disk is below the surface of the pool at all times.

Asample container IG, in the general form of a test tube that is shorter and of smaller diameterthan the Well, is provided. As shown in Fig.A 1, it is disposed in the well itself.

The sample container or tube is provided with a filling tube l1 attached to its upper side wall and extending vertically upward. As shown in Fig. V1, the upper end of this tube is sealed.

A second porous disk I8 corresponding in diameten to the interior diameter of fthe.. sample tube slightly below its upper edge. This disk is likewise made of small particles of glass sintered together. The portion of the sample tube eX- tending above the second disk comprises an auxiliary well I9.

The use of the apparatus of Fig. 1 is as follows:

With the sample container removed from the well, it is evacuated through the filling tube while it is held vertically, with a small pool of mercury overlying its porous disk, so as to form a seal. When the tube has been evacuated, a sample of light fluid, say a gas sample, is introduced into the container and the filling tube is sealed, for example by means of a flame in the usual laboratory tube-sealing procedure, while the sample tube is chilled to condense the sample in the lower portion of the sample tube.

The sealed sample container may be stored indefinitely in an upright position so that its porous disk remains covered by the mercury pool.

When it is desired to introduce the sample into an analytical apparatus, say a mass spectrometer, the sample container at approximately room temperature is lowered into the pool and then raised so that the two porous disks I5, I8 come in contact with each other. Suction applied tothe conduit I3 will cause the sample, say a light hydrocarbon gas, to be sucked up through the two disks into the conduit and thence to the analytical apparatus (not shown), while the mercury of the pool seals the apparatus from the atmosphere.

The apparatus of Fig. 2 comprises the well -IU having the enlarged upper section II and containing the mercury pool I2. The sample conduit I3 is similar to that of Fig. 1 and is provided with a similar porous glass disk l5 attached to its lower end under the mercury pool.

The sample container of Fig. 2 differs from -r that of Fig. 1 in that it is a relatively large glass bulb 20 having a vertical iilling tube ZI attached at its upper end. A freezing-out tube V22 projects downwardly from the bottom of the container. It has a side branch 2S extendingr horizontally approximately midway down the tube. The side branch turns upward into a vertical section 24 which contains a porous disk 25. This disk is disposed slightly below the top of the tube to provide an auxiliary well 28.

The use of the apparatus of Fig. 2 is in general similar to that of Fig. 1. The sample container is evacuated through the lling tube; the sample is admitted through the lling tube: the container is refrigerated, say by bringing it into contact with liquid nitrogen or the like, to cause any gases to liquefy and pass into the freezingout tube. The filling tube is then sealed with a flame.

The lling and freezing-out operations are conducted with the apparatus held in a vertical position so that the porous disk remains covered by a pool of liquid mercury in the well 26.

The sample in the container may be stored indenitely. When an analysis is to be conducted, the container is disposed as shown in Fig. 2 with the two porous disks in contact with each other, and suction is applied to the tube I3 to cause part of the content-s of the container to be with-v drawn through the two porous disks.

In the apparatus of Figs. 1 and 2, the well I and withdrawal tube I 3 preferably remain stationary while the sample container with its attachediseal is moved. In the 3, 4 and 5,

` l apparatus of Figs. 1t 1s convenient to keep the sample container stationary While moving the suction conduit and its attached seal. Referring to the latter gures, it will be seen that the sample container 3B is an upright bulb of glass or the like with a freezing-out tube 3| on its lower end and an upwardly projecting neck 32. A filling tube 33 is connected to the side of the neck and projects upward. The porous disk 34 is fastened in the neck slightly below its mouth to provide a f well 35 overlying the porous disk and containing a pool of mercury.

A sample withdrawal conduit 35 of relatively large diameter projects through a stopper 31 of glass or the like and is sealed thereinto. The lower end 38 of the sample withdrawal tube is of relatively small diameter and is sealed at its lower end by a small porous disk 39 of sintered glass. An auxiliary well or cup li is attached to an upwardly projecting rod 5I that passes between a set of guides t2, 43 formed integrally with the upper portion of the withdrawal tube. A helical spring i4 holds the rod to the side of the tube and it permits the rod to be slid upwardly and downwardly with respect thereto and also to be rotated so that the auxiliary well can be turned away from the lower end of the tube with its sintered disk. As shown in'Fig. 5, the withdrawal tube is kept sealed when not in use by placing the auxiliary well around the lower end of the tube, thus covering the sintered disk with a pool of mercury 45 retained in the well.

The use of the apparatus of Figs. 3 to 5 is as follows:

The container 3U is filled with a gas sample as described for the previous cases and the filling tube is flame-sealed after the sample has been frozen out. To withdraw gas from the container, the end of the withdrawal tube is inserted into the well 35 with the auxiliary well All covering its end. The auxiliary well is then rotated and raised out of the pool 35 and the two sintered disks are brought in contact with each other. If suction is applied to the withdrawal tube, gas from the container will pass through the two sintered disks into the withdrawal tube and thence to the analysis apparatus (not shown).

`To protect the withdrawal tube and its attendant apparatus from damage when it is not in use, a cap inthe general form of a test tube is provided. This cap has a 'neck 5| into which the stopper 31 ts.

The withdrawal tube should be maintained in a substantially vertical positionat allitimes so as to keep its end sealed. Y

The three types of apparatus just described preferably are constructed entirelyof glass, save for the helical spring Ml and, of course, the mercury pools. The large sintered disks I8, 25, 34 may be commercial 10 mm. sintered glass disks or immersion filters of "line porosity. These disks should be covered at all .times with mercury to a depth of about 10 mm. to prevent the entrance of air into the vessel.

The small sintered disks 39, I5 are not available commercially but may be made in the laboratory as follows:

Pieces of Pyrex glass tubing are thoroughly A small quantity ofv thev powderedv glass sthe' placed on a fiat surface and the tapered end of the glass tube is pressed into the pile. A close-fitting glass rod is inserted into the top of the tube andthe powdered glass is tamped into the tapered end until a packed layer about 2 mm. deep is formed. The tube is then carefully transferred, tapered end down, to the carbon mold, care being taken not to disturb the loosely consolidated particles of glass tamped in the end. After transfer, the powdered glass is given a final tamping with the glassv rod and the mold containing the tube and its contained glass particles is placed in a muffle furnace and held at approximately 1800 F. for several minutes or until the protruding portion of the glass tube sags to an almost horizontal position. The mold is then removed from the furnace and allowed to cool. Thereafter the tube is removed from the mold.

It will be found that the powdered glass has sintered together but that it has shrunk away from the glass tube slightly. To effect a tight seal between disk and tube, a carbon rod is drilled with a tapered hole large enough to allow the sintered end of the glass tube to just enter. The glass tube is then cut off and sealed to a short length of larger tubing which acts as a handle, and the carbon rod containing the tapered` hole is heated with a torch to a red heat. The flame is then removed, and the sintered disk and tube are quickly pressed into the hole and rapidly rotated. This swages the glass tube around the sintered disk and provides a tight seal.

To test the seal, the open end of the tube is connected to a vacuum system and the sintered disk immersed in mercury. If no mercury leaks through when the tube is substantially completely evacuated, it is satisfactory in this respect. The tube is then removed from the mercury. If air now leaks through the disk into the vacuum system, it is sufficiently porous for use.

Heating time, the amount of swaging, and the glass particle size distribution are factors in the determination of final porosity.

The manufacture of the additional parts of the apparatus is conducted by standard glass blowing procedures.

The apparatus has been described as applied to the samplingl of gases and it will find its principal utility in this field. However, it may be adapted for use with light liquids. For example, the apparatus of Fig. 2 may be used to transfer liquids from the container into the conduit i3, provided that there is a sulcient amount of liquid in the container to provide a slight head on the two sintered disks when they are placed together.

All three types of the apparatus described have been found exceedingly useful in the transfer of gas samples into various types of analytical apparatus, including both infra-red and mass spectrometers. 'I'he mercury maintains a thoroughly tight seal around the two disks and, if the manipulation is properly conducted, there is Substantially no danger of leakage from the outside.

We claim:

1. In apparatus for transferring a relatively light iiuid, the combinati-on which comprises a conduit, a well, a pool of heavy liquid in which the light fluid is substantially insoluble and immiscible disposed in the well, a porous member communicating with the conduit and covered by the pool and pervious to the light fluid but impervious to the heavy liquid, a container for the light fluid provided with a second porous member having characteristics similar to the rst member, the second porous member being so connected disposed above and attached to the second porous member, and a second pool of the heavy liquid in the second wellcovering the second porous member, the second well being small enough to fit in the first well.

3. In apparatus for transferring a relatively light fiuid, the combination which comprises a conduit, a main well, a pool in the main well of heavy liquid in which the light fluid is substantially insoluble and immiscible, a porous member communicating with the conduit and covered by the pool and pervious to the light fluid but impervious to the heavy liquid, a container for the light fluid provided with a second porous member of characteristics similar to those 0f the first, an auxiliary well disposed above and attached to the second porous member, an auX- iliary pool of the heavy liquid in the auxiliary well, the latter being small enough to permit the second porous member to be brought in contact with the first member in the main pool and permit the flow of the fiuid from the container into the conduit through the two members, and means for producing a pressure differential between the container and the conduit to induce such flow.

4. Apparatus according to claim 3 in which the second porous member is mounted on the top of the container in the auxiliary well.

5. Apparatus according to claim 3 in which the second porous member and the attendant auxiliary well are connected to the container by a tube adjacent the lower portion of the container.

6. Apparatus according to claim 3 in which the heavy liquid is mercury.

7. Apparatus according to claim 3 in which the porous members are composed of siliceous particles sintered together.

8. In apparatus for transferring a relatively light fluid, the combination which comprises a conduit, a container for the light fluid, a first porous member forming an opening in the container pervious to the light uid, a second po'-V rous member also pervious to be light uid and disposed in the end of the conduit, one of said porous members forming the bottom of a well, a pool of heavy liquid in which the light fluid is substantially insoluble and immiscible disposed in the well, the two porous members being impervious to the heavy liquid and being adapted to be brought in Contact with each other in the pool, auxiliary means for sealing the other of said porous members when it is disposed outside the pool, and means for producing a pressure differential between the container and the conduit when the two porous members are in contact within the pool.

9..In apparatus for transferring a relatively light fluid the combination which comprises a laiirst well, la pool ofiheavy liqui'dnwhich the Vlighi'fuid is lsubstantially insoluble and im- Vof`light 'fluid from the container into the conduit 'through `the porous members, Aandv a second independentI well filled with the heavy liquid and adapted to seal the first porous member when the `firstV porous member/is removed from the rst well.

'10. Apparatus according to c1aim9 whereinthe second'well comprises a, cup having an elongated support arm secured to the conduit in rotatable and longitudinally slideable relationship.

JAMES B. HUNTER. ROBERT C. TAYLOR. `WILLIAM S. YOUNG.

REFERENCES -CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,770,012 Randall July 8, 1930 '2,125,910 Gardner Aug. 9, 1938 

